Refrigerating system



March 17, 1931- R. E. SCHURTZ REFRIGERATING SYSTEM Filed Dec. 2Sheets-Sheet l March 17, 1931. R SCHURTZ REFRIGERATING SYSTEM 2Sheets-Sheet 2 Filed Dec. 20, 1918 5140\2444106 12. E Sc/zurfz PatentedMar. 17, 1931 UNITED STATES- PATENT OFFICE REFBIGERATING SYSTEMApplication filed December 20, 1918. Serial No. 267,614.

The invention has for-an object to'eifect improvements in refrigeratingsystems-of the still, condenser, absorber type, having for its primarypurpose the attainment of a satisfactory apparatus for the completesystem which will be fully automatic in its operation, so that it may besafely left without attention for a considerable period of time.

It is an important purpose to provide an apparatus which will operatecontinuously for the transfer of li uid such as aqua ammonia from theabsor er to the still, and to convey weak liquor from the still to theabsorber with regularity, so that there will be no intermission of itsessential functions, and not only that, but to obviate excessivefluctu-' ations in the refrigerating action of the system. For theattainment of these ends, therefore, the invention involves improvementsin structure combination and arrangement of elements whereby theirproper coordination for the ends in'view is attained, as will appearmore particularly from the description hereinafter, and'the drawings,wherein,

Figure 1 is a diagrammatic detail of a system constructed in accordancewith my invention, with certain detailsof structure approximatedsufliciently'to enable the construction of the apparatus by those versedin .the art. I

Fig. 2 is a detail of a transfer ap aratus associated with the still andabsorber or conveying strong liquor from the latter to the formerr Fig.3 is a detail of avalve element therein, Fig. 4 is a horizontal crosssectional view of the transfer elem Fi 2,

ig. 5 is a detail sectional view on the line 5-5 ofFig. 2. i Fig. 6 is adetail horizontal sectional view of the valve shown in Fig. 3, on theline 6-6 of Fig. 2. S 7 There is illustrated an apparatus operative'on'the principles well known in such systems,.including a still 10, arectifier 11, a condenser 12 for gas distilled, a collector 13 forliquefied. or condensed gas, the expansion chamber or coils 14, andabsorber 15, these being elements well known in such apparatus,

ent, on the line44 of heated by means of a burner 10, supplied byfuelfrom a pipe 16, forming the outlet from a valve casing 17 includinga tubular portion 18 fitted in-- the heads of the still chamber andextending entirely across the still and projecting therefrom at eachend. a short distance. At one end, adjacent and outwardly of the pipe16, a concentric seat 19 is formed in the tube against which there isadapted to. seat a thermostatic valve bar 20, mounted slidably in thetube 18, its end opposite the seat 19 being engaged by an adjustingscrew 21 fitted in the end of the tube. Outwardly of the seat19- a pipe22 is connected with the casing, by which fuel is led thereto to beadmitted through the seat 19. From the upper part of the still distilledvapor is carried through a rectifying coil 23 enclosed in a jacket 24through which liquor returned from the absorber is passed, and from thisrectifier a pipe 25 is extended to an anti-siphon trap 26, located abovethe normal liquorlevel of the collector 13. This trap comprisesessentially a closed receptacle into the upper part of whichthe pipe 25leads, a pipe 27 having an end portion proected through the bottom ofthe receptacle, extending from the condensing coil 12, and ananti-siphon loop 105 leading from the top of the colle ctorandterminating near the bottom of the trap 26. The pipe 27 communicateswith the collector 13, at its lower part as will be readily understood.It is connected to the coil 12 at a point intermediate'ly of. the heightof the coil, which in the present instance includes a plurality ofhelices arranged on a vertical axis. The coil at the lowertermination'is provided with an upward extension 28, leading into thebottom of the collector 13, While the upper end of the coil is similarlyconnected to the collector. This results in a circulation of theliquefied ammonia throughfithe coil 12 from the collector 13 and rapidcondensation,

as is well understood:

is carried bythq pipe 29 to the expansion-'- 001114, an expansionvalve30 being provided From the collector13 thecondensed liquid at thepoint of entrance of the gas to the expansion coil. I form a coil 31beneath the absorbing chamber, having its upper ter minal leading intothe base of the absorber, while its lower end is connected by a verticalpipe 82 to the absorber intermediately of its height, and preferably ashort distance below the normal liquor level in the absorber. The returnpipe 33 from the expansion coil is con nected to the coil 31 near itslower part Movement of liquor The foregoing includes the apparatus andfunction of the invention in the complete movement of gas in the systemfor refrigeration, from its distillation to its absorption. Movement ofliquor is attained by forming a connectionwith the still in the form ofa pipe 40, leading through the heat exchanger 41 to the upper part ofthe absorber, from whence it discharges by-pipe 18 into a sealedreceiving tank 42 forcooling weak liquor, this tank having communicationwith the upper part of the absorber through a pipe 1 43 the receivingend of which projects a dis tance above the bottom of the tank 42. Inthis way the pressure existing in,the absorber is always communicated tothe tank 42, and to govern the flow of liquid into the tank, a specialformation of valve shown at 44 is employed (see Fig. 1).

Control of absorber liquor replenishment The valve includes a lowercasing section 45 having a drain outlet leading into the upper part ofthe tank 42 so that gas pressure in the tank 42 is freely admitted intothis section. A conduit terminal 46 is provided in the casing section45, forming a continuation of the pipe 18' which discharges thereinto,this terminal 46 having a port in its upper side centrally of the casingsection 45, and upon the section 45 a. cap 47 is provided, a diaphragm48 being secured between the section 48 and the cap. A valve 49 isprovided upon the diaphragm movable to engage over the port of theconduit terminal 46 for closure thereof under downward pressure of aspring mounted in a suitable cylindrical extension of the cap, andadjustable to vary its expansive force by means of a screw 50 engagedthrough the top of the cap. The spring is of suitable proportions to'enable its adjustment to balance both the,

gas pressure of the absorber exerted against the diaphragm and thepressure in the conduit terminal 46 exerted against the valve 49.

Transfer from absorber to still Above the level of the still 10 and ofthe level of the rectifier 11 there is located a transfer device 55, bythe action of which, Whenever the liquor in the absorber is above apredetermined level, regular transfer of liquor from the absorber to thestill will occur,

without interrupting the operation of the still or of the absorber. Thisdevice comprises a cylindrical tank receptacle 56 as illustrated in thepresent instance, arranged on a vertical axis, having a head portion 57and closed at the bottom by a plate 58 as illus. trated. The head 57 isformed with a central hollow neck 59 (see Figs. 2 and 3) of cylindricalform provided-with a port 59' at one side, around which a smoothlyfinished seat is formed upon which there is slidable a valve 60 adaptedto close the port. The valve comprises a segmental plate carried looselyin a box 61 mounted upon a valve shaft 62 concentric with thereceptacle.

The box 61 conforms to the shape of the valve 60, but is of a size tohold the plate loosely, as indicated, a spring 63 being interposedbetween the valve and box to hold the valve against its seat. In theneck 59 there is an intermediate horizontal partition 64, in which theupper end of the. shaft 62 is journalled, the lower end of the shaftbeing journalled in the bottom plate 58. The partition 64 and bottomplate 58 are formed with a plurality of small ports 65 and 66, and overthese atthe outer sides there are valve disks 67 loosely splined uponthe shaft 62. The valve disks are ported so as to simultaneously uncoverthe ports 6566 at one position, and to close them at another, underrotation of the shaft 62. The outer end of the neck 59 is closed bymeans of a top cap plate 69, while around the lower valve 67 there isformed a flange70 on the bottom plate 58, to which is secured a bottomcap late 71. The two cap plates lastmentioned are fitted to receive pipeconnections for the conduction of li uid to and from the receptacle, andupon t eir inner sides are rovlded with springs 72 bearing against t erespective valve disks to hold them properly in seated positions.Connected to the neck 59 for the deliver of liquor to the port 59 thereis a pipe 73, aving a siphon loop 74 t erein (see Fig. 1) with its bightportion disposed upwardly,'on or closely adjacent the predetermined ornormal high level of liquor in the absorber, the receptacle 56 beingdisposed a suitable distance below that level, and one side of the loopbein led into the absorber near its bottom, a though it may be spaced asuitable distance from the bottom to avoid removal of weal: lig uortherefrom. The top cap plate 69 (see ig. 2) has a pipe 78 suitablyconnected thereto leading from the duct 25 and rectifier coil 23, whilefrom the bottom cap plate a liquor duct 77 is extended to the jacket 24of the rectifier 11, into which it discharges. From the rectifier jacketthe liquor is carried by the pipe 77 through the exchanger 41 to theupper part of the still 10. From the upper part of the pipe loop 74 agas pipe 79 is extended into the receivin tank 42 of the absorber,before mentione iao A small vertical loop 76 is formed in the pipeadjacent the transfer device 56. This will indicate the pressure in thestill at all times.

:rection of the shaft '62.

Operating means of transfer device (see Figs. 2, 4 and 5) Within thetank 56, adjacent its lower part there is mounted a bellows 83 which maybe spring expanded if the structure of the bellows does notserve thesame function. It is connected by a pipe 84 to the upper part of theabsorber. Connected with the movable element of the bellows toreciprocate therewith there is a horizontal rod 84' the support forwhich comprises arms 85 and 85 of a bracket secured to the inner side ofthe receptacle 56, an intermediate sto 86 being also formed on thisbracket. T e outeror left hand end of the rod 84 is slidably mounteddirectly in the bracket arm 85, while at its inner part, adjacent thebellows, the rod= is engaged slidably in a slide or sleeve 87 which isitself slidable in "the arm 85'. The sleeve has flanges 87' and 88' atthe right and left of the arm 85 and a heavy spring 88 is confinedbetween the flange 88 and the bracket arm 85.

Upon the valve shaft 62 there is secured an arm 89, by which the shaftis rocked to operate the valves 67 and 63. This arm normall engages theside of the stop 86 opposite the ellows, the, valves being then closed.The arm is held against the stop by a light spring 90 confined betweenthe arm 89 and the bracket arm 85.

The sleeve 87 is longitudinally slotted, and a key 91 is provided on therod 84' slidable in the slot of the sleeve. Transversely arranged uponthe inner end 92 of the sleeve there is pivoted an L-shaped trigger 93,

'which is a lever of the first order, the pivot being intermediately ofits lower short arm, and this arm extends outwardly from the di- Thetrig er has a downwardly. extended bill 94 at -its ower extremityadapted to interpose in the path of and to be engaged by 9. lug 95 onthe rod 84 at times to move the sleeve 87 to the right.

llhe upwardly extended arm 99 of the trigger is arranged to engage thelower side of a float 96 when the float approaches the lower limit ofits movement. The float 1s fitted in the tank 56 as snugly as possiblewhile permitting free movement, and theshaft 62 passes looselytherethrough. Upon the lower side of the float there 15 mounted astirrup 97 close to the arm '89 and locatedto engage under a tongue 98projected from "the trig- -commercial aqua-ammonia.

ing the absorber tank 15.

ger through the stirrup. The arm 89 on the shaft 62 has a lateral strike100 thereon extended toward the trigger positioned to be engaged by aheel 101 at the junction of the upper and lower arms of the trigger whenthe sleeve 87 is moved from the right hand position shown in Figures 2and 4. Under pivotal movement of the trigger when borne downwardly bythe float, the heel 101 will pass below the level of the strike 100 ofthe valve shaft arm 89 and the bill 94 will soon after rise above thelug 95. i I

A diagonal pipe 73' is shown'extending from the upper part of theabsorber into the loop 74, and preferably extends downwardly into a trapenlargement 74' formed midway of the'loop and extending downwardlytherefrom, into which the pipe 84 also opens at the bottom. Thisfunctions in case high pressure should develop in the absorber tendingto back liquor from the absorber into the tank 56. If such tendencyshould develop the gas from the upper partof the absorber would simplybubble into the trap when the level in the absorber is below the loop74. The pipe 7 3' being submerged and requiring only to be quite small,when gas is released from the transfer device, it will follow the easierpath through the pipe 7 9 rather than follow pipe 73.

Operation. of the system In use, the elements being assembled in thenecessary relation, to initiate operation of the apparatus, it issuflicient to introduce into the still and into the absorber suitablebulks of The fuel conduits of the burner being connected to a properfuel supply, the burner may be lit and distillation initiated. Thevaporresulting; passes through the coil 23; passes thence through trap26 and pipe 27 entering the condensing coil a little above its lowestpart and reaching the collector 13. At this pbint it will have beenreduced to liquid form after; sufficient pressure has been developed.After passing the expansion valve 80 or 125 and being evaporated in thecoil 14 it will return through pipe 33 to the absorber coil 31, enteringthis a distance above its lower part andv by its buoyancy will moveupward along the coil in small bubbles which are quickly absorbed eitherin the coil or soon after enter- This gas mpvement carries liquorthrough the coil br1ng-- ing fresh liquor constantly in contact with theentering gas and usually insur ng absorption principally in the coil. Intime the liquor in -'the still will have been largely deplated of itsammoniacal content making 1t. suitable for transfer to the absorber. Thereturn and absorption of gas from the expansion coilalso raises thepressure in the absorber. This finally acts on the diaphragm 48 of thevalve 44 and permits pressure in;

the still to force liquor from the still through the pipe 40, theexchange element 41 and pipe 18 past the valve roper 49. The tank 42then fills and over ows through the pipe 43 to the absorber tank 15.

Admission of fresh weak liquor to the absorber quickly lowers pressuretherein and on the diaphragm 48, which permits the spring pressed valve49 to close, cutting off further movement of liquor from the still forthe time being. Should the temperature rise above a predetermined degreein the still, this will involve functioning of the thermostatic device1720 to diminish the supply of heat. Accretion of strong liquor from thetransfer device 55 will result in reverse operation of this thermostaticdevice to restore the still to full activity.

Meantime, the absorber having been filled above the loop 74, liquor willhave already gravitated into the transfer device 55 through pipe 73 andport 59valve 60 being open and valves 67 closed. At this time thebellows are in open condition by pressure from the absorber through pipe84 which is exerted at all times. The spring 88 holds the arm 89 to theleft, compressing the spring 90. The

lug 95 is alittle to the left of the trigger, and the trigger will havebeen borne upon previously by the float so that its heel 101 bearsagainst the arm 89 transmitting pressure of the spring 88. The bill 94is above the level of the lug 95, which is at the left.

As soon as the entering liquor raises the float sufficiently, thestirrup 97 lifts the trigger, bringing the bill 94 below the lug 95 andthen clearing the heel 101 from the strike 100 of the arm 89 and thisclearance permits the arm 89 then to swing against stop 86 by pressureof weak spring 90 to close the valve 60 and open valves 67 at top andhottoin. Gas from the still at once enters at the top from pipes 25 and78 and permits the liquor to drain rapidly through pipe 77 to rectifierjacket 24, after filling of which liquor may overflow therefrom throughpipes 77' heat exchange 41 and pipe to the still.

It should be noted that the relative sizes are not correctly indicatedin the drawing, certain parts. having been enlarged to enable clearrepresentation.

The entry of still pressure to the tank 56 overbalances the absorberpressure in the bellows and the tendency of the bellows to remain open,and collapses them, moving the rod 84' to the right, the lug 95 engagingbill 94 and pressing the trigger and slide to the right compressing theheavy spring 88 against the arm 85. The trigger will then be in positionso that when the float falls sufiiciently to again depress the trigger,the heel 101 may engage the strike 100 when the heavy spring is nextreleased by lifting of bill 94. Immediately after this, the stillpressure in the tank causes a somewhat violent escape of gas from tank56 through 74 and 76 to the receiving tank 42 of the absorber, wherebyan agitation of the cooled weak liquor therein is caused which resultsin almost instantaneous absorption of the gas entering. This obviatescreation of excessive pressure in the absorber and resultant decrease ofefficiency of refrigeration by raising the boiling point of ammona.

In the present instance the condenser, collector, and absorber, togetherwith their immediately appurtenant parts, including the trap 26, are alldisposed within a suitable large tank 106 into the bottom of which coldwater is admitted through the connection 107, a drain connection forthis cooling tank being provided at 108 at its upper part. Thecondensing coils under this arrangement get the advantages of themaximum cooling effect of the water while the remaining elements areaffected sufiiciently to meet their need for cooling as will be readilyunderstood.

By forming the float 96 of a size and shape to nearly divide the upperpart of the chamber from its lower part, not only is the transfermechanism operated, but it is made possible to utilize the gas directfrom the still as one of the principal actuating agents, without theexcessive loss of gas by absorption in the transfer device, owing to thefact that the float covers practically the whole of the surface of theliquid in the transfer device.

It may be noted that in my system it is possible to do without a heatcontrol device of automatic form, if desired, permitting the burner orother heater to be set by hand, and the machine will then operateautomatically otherwise.

The means responsive to action in the absorber and the still referred toin claim 3 hereinafter, is intended to designate the transfer apparatusincluding elements single or plural acting by increase or decrease ofliquor weight, liquor level, or gas pressure, or two or more of these,to effect its operation.

I claim:

1. In a refrigeration system of the character described, a still, acondenser, an absorber, a liquefied gas collector, an evaporator andconduits connecting the above mentioned elements, in combination withmeans responsive to pressure in the absorber to- I gether withthermostatic means associated with the still, both constructed to governthe strength of the liquor in the absorber and the still so as tomaintain with close approximation a uniform quantity of liquefled as inthe liquefied gas collector.

2. n a refrigeration system of the character described, a still, aheater 'for the still, a condenser, an absorber, a liquefied gascollector, an evaporator and conduits connecting the above mentionedelements, in combination with means responsive to pressure 111 theabsorber, thermostatic means associated with the still constructed toregulate the heat- 7 er and means constructed to respond to overflow inthe absorber operatively associated-' with the still, the several ofsaid means 00- operating to maintain a close approximation of a meanstrength in and a meanquant'i ty of, the liquor in the absorber and inthe still, to maintain With close approximation a determined quantity ofliquefied gas in the liquefied gas collector.

3. In a refrigeration system of the character described, a still, acondenser, an absorber, a liquefied gas collector, an evaporator RALPHEDWARD SCHURTZ.

